Fleck 5600/Foregin Pieces in Cylinder

My Fleck 5600 recently started jamming so I replaced the pistons, seals and spacers. The old ones were not in terrible condition. However, at the bottom of the cylinder I found three plastic pieces (photo below). I suspect that this was the culprit. What I am wondering is where these came from??

When you say "cylinder" I suspect you mean the resin tank. If so the parts couldn't have gotten up into the valve or cause problems unless they got down to the bottom basket and even then, that would maybe reduce a teeny tiny bit of water flow but that's it.

There are other causes of a 5600 jamming and usually you can't see why by looking at the seals and piston, or brine valve.

No, I did not mean the resin tank when I used the term "cylinder". I was referring to the housing that the piston assembly fits into. At the bottom, underneath the piston assembly, is where I found these pieces.
The valve is working fine now...

I think I just answered my own question...
A couple of weeks ago, I had a problem with my well pump. I pulled the pump and discovered that the check valve, which is integral with the pump head, had broken. Here is a pic of the check valve....